FIG 7.

Overexpression of Erg11 can partially suppress the HU sensitivity but not the cold sensitivity of the hem13-1 mutant. Erg11 was expressed on an S. pombe expression vector in wild-type, erg11-1 mutant, and hem13-1 mutant cells under the control of its own promoter (marked on the right). The rad3Δ checkpoint mutant was used as a control. Serial dilutions of the S. pombe strains, which are labeled on the left (see strain list in Table S1 in the supplemental material), were spotted on YE6S plates or YE6S plates containing 2 or 3 mM HU. The plates were incubated for 3 days at 30°C and then photographed. Since the hem13-1 mutation causes cold sensitivity, one of the YE6S plates was also incubated at 22°C for 3 days (second from the left). V, empty vector control.